/*
* $Id$
*
* resolver related functions
*
* Copyright (C) 2006 iptelorg GmbH
*
* This file is part of ser, a free SIP server.
*
* ser is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version
*
* For a license to use the ser software under conditions
* other than those described here, or to purchase support for this
* software, please contact iptel.org by e-mail at the following addresses:
* info@iptel.org
*
* ser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*

* A callback should return one of:
* DST_BLACKLIST_CONTINUE - do nothing, let other callbacks run
* DST_BLACKLIST_ACCEPT - for blacklist add: force accept immediately,
* for blacklist search: force match and use
* the flags as the blacklist search return.
* ( so the flags should be set to some valid
* non zero BLST flags value )
* DST_BLACKLIST_DENY - for blacklist add: don't allow adding the
* destination to the blacklist.
* for blacklist search: force return not found
*/

* is used (use 0 to free all of them)
* delta - consider an entry expired if it expires after delta
* ticks from now
* timeout - exit after timeout ticks
*
* returns: number of deleted entries
* This function should be called periodically from a timer
*/